It isn't that it is hard to believe it can happen. It is so many people, though, that it is hard for me to comprehend.
And yes, the mask can make noise, but typically not as much as the person makes snoring for your partner. Modern ones, in particular, are fairly quiet and can be tucked under the night stand such that they make about as much noise as basic forced air venting systems do. Which is not much.
The mask can be uncomfortable some nights. They do have a variety of masks to try, though. And if it isn't working, they have other options.
That last point is actually refreshing for me in this story. So many bounce off a CPAP into nothing. Hopefully efforts like this story will help people find something that can work.
My swift pillow on a Resmed A10 is 0db. I can’t tell if it’s running sometimes. It’s not for everybody but people should expect to have to experiment for a few weeks.
Your partner hears it, you may hear it when it has moved a bit and the air is leaking, you hear it when you try to go to sleep and the overpressure safety valve is next to your pillow and making a wheezing sound, when you end your sleep cycle and could go to another one except that the mask moved a little and it's bothering enough to wake you up (and then you have to find sleep again), you worry about keeping it and yourself in just the right position that will allow you to go back to sleep, effectively preventing you from falling asleep because of the stress...